Japanese Unexamined Patent Application Publication No. 2006-289562 discloses a vibration reduction handle of a grinder as a hand-held power tool. The vibration reduction handle comprises a handle body, a cylindrical grip portion and a vibration reduction rubber. The handle body is made of metal and detachable to the hand-held power tool. The cylindrical grip portion is made of plastic and rotatably connected to the handle body via a rounded surface. The vibration reduction rubber is defined as an elastic member biasing the cylindrical grip portion in a state that the cylindrical grip portion rotates against the handle body. Therefore, a vibration from the handle body to the cylindrical grip portion is reduced by means of the vibration reduction rubber.
Regarding the vibration reduction handle described above, when the cylindrical grip portion is biased by a bending force and rotated around the rounded surface, a forward part of the vibration reduction rubber with respect to a direction of a rotation is compressively deformed and therefore the vibration reduction rubber reduces the vibration. However, reducing the vibration by means of the vibration reduction rubber is not attained by a tensional deformation but a compressional deformation. In this point, as to the vibration reduction rubber described above, a backward part of the vibration reduction rubber with respect to the direction of the rotation is stretched, therefore the tensional deformation is wasted to obtain a vibration reduction effect effectively. Namely, because the vibration reduction rubber is only partially compressively deformed, the vibration reduction effect is inefficient.